In the Garden:New England
August, 2008
Regional Report

Solutions for the Rain-Soaked Garden

This would have been the year to garden in raised beds. Actually, this would have been the year to grow everything in containers that could at least have a hope of drying out before the next deluge. The community gardens at my office squish under foot; beans at home are rotting, tomatoes have blight, crab apples have scab, and slugs are as big as school buses. The 10-day forecast is in a continual loop: heavy rains, flooding, dangerous cloud-to-ground lightning. Quarter-sized hail is the only prediction that we've escaped, thankfully, or we would probably have no plants left to fuss over. Plants and gardeners alike are starved for even two consecutive days without rain.

The end of summer is approaching but there are weeks of growing time left, so it's worth trying to salvage flowers and edibles, and even planting fall crops in case the current weather trend takes a turn for the better. Here are some things that can help.

Muddy Ground
Wet soil is much more easily damaged by our footsteps than dry soil. It compacts and gets depleted of air that plant roots need to survive. Be especially careful when walking among plants, and lay boards or straw on walkways to soften the impact.

On the other hand, if the soil at the base of plants is staying too wet, remove straw or other mulch that's close to the stems so the soil can dry out a bit.

Wet soil can be further damaged if you try to till it or disturb it too much when preparing to plant fall crops. Pull up spent veggie plants to remove any disease they might be harboring, and then leave the soil alone. If you need to break up the soil to plant for fall, use a garden fork and loosen the top few inches without digging deeply.

Improving Air Circulation
The foliage of many plants has overgrown from all the rain, and it's turning yellow and rotting because it's staying too wet. It's time for a drastic foliage trim, especially stems that are lying on the ground. I've drastically cut back lady's mantle, poppies, and catmint, among others. I lifted up some pansies at the edge of a bed and found a convention of snails, so I pulled up the plants, which fade anyway at the end of season. If you have annuals that are flagging, removing them will improve air circulation around their neighbors and give them a chance to dry off.

Slugs and Snails Begone
These pests are beneficiaries of wet weather, and in addition to shoe patrol there are some repellents worth trying. Coffee grounds repel them; the higher the caffeine, the better. Spread a layer of grounds around plants. They also provide a little nitrogen.

Numerous commercial baits are available. Those that contain metaldehyde are toxic to mammals (as in your pets and you), so they are best avoided. Beer works as a lure. Commercial beer traps are basically shallow saucers that you fill with beer. You can make your own using tuna cans. Just keep the surface of the trap above the soil level so you don't inadvertently trap beneficial beetles and the like.

Diatomaceous earth has some effect against slugs when they crawl along the sharp-edged particles. But my favorite option is poison bait containing iron sulphate, which is toxic to slugs and snails and also provides some nutrients for the soil. Brand names include Sluggo and Escar-Go. These are pellets that you sprinkle around plants.

You can buy strips of copper to wrap around containers to repel slugs and even wider strips to set in the ground like fencing around plants. This can be a pricey option but they are effective if they form an unbroken barrier.

Diseases That Love Moisture
Tomato diseases cause much distress to gardeners longing for a plentiful harvest of juicy tomatoes. Leaf spot diseases are generally caused by fungi and they can spread rapidly in moist conditions. Mulch beneath the plants can help curb the spread because the spores can't bounce up onto the plants from the soil. It's not too late to put down a protective layer of straw. Pick off affected leaves to curb the spread. Copper fungicides can help, just avoid overdoing it because copper can be toxic. Serenade is a relatively new biocontrol for several fungal diseases that works by boosting the plants' natural immune system as well as by inhibiting fungal germination and growth.

Verticillium wilt and fusarium wilt cause yellowing and wilting leaves, and eventually loss of foliage. There's nothing to do but pull up wilted plants or leave those not severely affected (but remove wilted leaves) in hopes the fruit will ripen.

A common disease of many flowers, such as bee balm, phlox, and zinnias, is powdery mildew, which causes a white coating on the foliage. It also often affects cucumbers and squash. Potassium bicarbonate-based products, including GreenCure and Kaligreen, can slow the disease progression.

Last but not least, here's an important tip that can be especially hard to follow this summer: Try to stay out of the garden when it's very wet. You could be inadvertently spreading disease from plant to plant.